Wireless communication networks are widely deployed to provide various types of communication such as voice, data and so on, for a number of users. The wireless communication networks are typically based on code division multiple access systems (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), Orthogonal frequency division multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA). For instance, Global system for mobile communications (GSM) is based on TDMA. Similarly, Worldwide Interoperability for Microwave Access (WiMAX), 3GPP Long term evolution (LTE) and 3GP22. Ultra Mobile Broadband is based on Orthogonal Frequency Division Multiplexing Access (OFDMA).
In a Worldwide Interoperability for Microwave Access (WiMAX) communication network a Mobile Access Service Network (MASN) forms the radio access network. The MASN refers to a set of network functions that provide connectivity services in form of Internet Protocol (IP) packets to mobile stations in the WiMAX network. Typically, the connectivity services include, but are not limited to, video streaming, vehicle tracking, file sharing, multi-media games, news and web browsing.
Typically, a wireless communication network includes a plurality of base stations, a plurality of mobile stations, one or more central controllers, one or more home agents and one or more content servers together with Authentication, Authorization and Accounting (AAA), Dynamic Host configuration Protocol (DHCP), Policy server etc. A set of base stations is usually associated with a central controller. For instance, Access Service Network Gateway (ASN-GW) functions as the central controller in a WiMAX network. Similarly, Mobility Management Unit (MMU) and Signaling Gateway (SGW) function as the central controller in the LTE network. The central controller communicates with the associated base stations to provide various connectivity services and transmits data in form of IP packets. For instance, a mobile station may request for radio access from a base station. In response to the request, the base station may communicate with the central controller to receive the relevant IP packets. The central controller can fetch the IP packets from the home agent or the content server before transmitting the IP packets to the base station. Thereafter, the base station transmits the IP packets to the mobile station requesting the radio access. Additionally, in some configurations, central controller may include a radio related component and a data related component which may be physically located apart from each other. Thereby, an IP packet may be routed from the content server through three intermediate routing points: the home agent, the central controller and the base station before transmission to the mobile station.
A transmission link between two successive routing points in the wireless communication network has a transmission cost associated with it. Typically, a transmission link connecting the content server and the home agent has the least transmission cost. However, the transmission cost increases as the IP packet is transmitted from the content server through each of the routing points to the mobile station. Consequently, the transmission link between the base station and the central controller may have a higher cost associated with it as compared to the transmission link between the home agent and the central controller, which, in turn may have a higher cost associated with it as compared to the transmission link between the home agent and the content server.
A mobile station in the wireless communication network may frequently undergo handover from a first base station to a second base station as it moves from the current cell area to any of the neighboring cell areas. In the existing methods, during the handover, the mobile station stops receiving the content from the first base station and the mobile station tries to retrieve the content from the second base station. Therefore, the second base station transmits one or more packets of the content irrespective of the content previously transmitted from the first base station to the mobile station. Thereby adding to the transmission cost associated with the link between the mobile station and the base station.
Further, during handover from the first base station to the second base station, transmission of a content to the mobile station may be paused. The reason for pausing of the transmission may be due to the unavailability of the content on the second base station. In such cases, the transmission is started once the content is fetched on the second based station. However, the pausing of the transmission may result in an undesirable quality of services (QoS). For instance, during music streaming or video streaming any pausing during streaming can disturb the continuity of the streaming and thereby reduce the QoS of streaming.
Additionally, the second base station may retrieve the requested content from the central controller, the home agent or the content server, after the handover, thus increasing latency in transmitting the content to the mobile station. Further, the mobile station may have to buffer the content already received from the first base station, before receiving the subsequent content. This may result in high transmission costs and may also cause the mobile station to experience a significant latency in receiving the content.